Molding of concrete pipes and the like



' Feb. 22, 193s. qc; HALKYARD 2,109,421

MoLnENE oE coNcEEEE PIEEs AND TEE LIKE Filed May 2e, 19:54

Patented Feb. 22, 1938 l UNITED STATES PATENT oFI-IcE MOLDING "F CONCRETE PIPEs AND THE LIKE a Charles Cyril Iialkyard, Melbourne, Australia,

assigner to Hume Pipe Company (Australia) Limited, Melbourne, Australia l n i Application May 26, 1934; Serial No. 727,817

I In Australia June 15, 1933 x 7 2 Claims. v (Cl. 25--30)` This invention relates to the molding of contially Compacts Seine in its-ennuie? OIIn. The crete pipes and the like including the lining of screeding member .is then removed and the mold metal or other pipes with concrete cr like mateor fcasing is subjected to` combined centrifugal rial. w and jolting actions by means of a suitable appa- 5 The specication of UnitedStates Patent No. ratus provided for the purpose. I v g 5 2,023,381 describes a method and'apparatus ac- It has been found that by retaining the screedccrding to which the moldingand lining of pipes ing member Within the InOld during the initial with concrete is'effected by subjecting theconrotatiOn and Charging thereof, the Subsequent crete mixture in a semi-dry or non-liquid'state combined centrifugal vand jolting process causes simultaneously to centrifugal force and to a prothe distributed and partially compacted semi-,dry 10 nounced jolting or ccncussional action within a Concrete mixture to be uniformlyand effectively rotating mold or casing which is intermittently Consolidated throughout the length and Circumand abruptly projected upwardly from its norference of the mold. Furthermore, relatively mal position of rotation and returns forcibly Small quantities 0f the Semi-dry material may thereto during such rotation. be introduced and compacted where necessary to 15 In accordance with the abovementioned procfill up any depressions or inequalities in the ess, the mold or casing is initially rotated withinner surface ofthe concrete pipe 01 lining. In out the jolting action whilst the concrete mixthis respect, it has been found hitherto that any v ture is being fed into the mold. Owing to its such additional material which may be introsemi-dry or non-liquid consistency, the concrete duced for thisgpurpose tends to remain loose 20 is not capable of flowing or spreading longituaround the interior of the pipe and forms a rough 'dinally within the mold as is the 'case when the or irregular surface. concrete is employed in the usual liquid or semi- Referring to the drawing which forms part of liquid state in the molding of concrete pipes by this specificationc the centrifugal-process. For this'r'ason, it is Y Figure l is a longitudinally contracted side 25 'necessary to evenly spread or distribute the elevation of apparatus according to one embodisemi-dry material into annular form within the ment of the invention.

mold before subjecting it to the aforesaid com- Figure 2 is an end view' of Figure 1. l bined centrifugal and joltlng action. Such even In the drawing the numeral 2 indicates a mold. spreading or leveling of the concrete is essential provided with the usual endrings 3 which nor- 3o Vgto the production of a pipe of uniform diameter mally rests upon runner wheels 4 mounted on c r y and thickness and maximum density. shafts 6 supported by bearings l on a framework 'In accordance with a preferred form of the 8. Suitable means, such as disclosed for instance invention, a screeding or leveling member, conin prior United States Patent'No. 2,023,381, may ssting of a straight length of tubing or' circular be provided to impart pronounced jolting or con- 35 section bar, is placed in position within the mold cussional action to the mold while it .is -being or casing so as to extend longitudinally therein rotated at high speed by the runner wheels I.

prior to the charging of the mold with the con- In Figures l and 2 the screeding member is crete mixture. Whilst the screeding member is shown in the form of a straight tube 9 which 40 held in position either manually or by suitable extends completely'through the mold and is sup- 40 mechanical means as hereinafter described, the ported so as to be spaced slightly inwards froml material is fed into the mold which is rotated at the usual inwardly projecting flanges 3a of the a relatively low speed, the result being that the mold end rings 3. Supporting means for the semi-dry material is evenly spread or distributed screeding tube may include pairs of laterally l by the screeding member into substantially an: spaced end brackets il' secured to framework 8 454 nular form throughout the length of the mold. and carrying laterally extending sub-frames I2 When substantially the whole of the charge of t0 which upstanding arms or bearers I3 are reconcrete has been thus introduced into the mold tained. These bearers are preferably vertically and initially spread therein by the screeding adjustable and for this purpose may havea vermember, the latter is allowed torotate while vthe tical slot I4 or a series of vertically spaced holes 50 rotation of the mold is continued at' relatively to pass bolts I6 which retain them to the sublow speed. whereby the leveling and pressure frames l2. f member exercises rolleil pressure simultaneously Each bearer is provided atlits upper end with upon the entire length of the charge and ensures a plate ll having an open sidedrecess I8 of apuniform distribution of the material and paiproximately semi-circular shape to accommodate `55 the screeding tube 9 so that it may rotate while bei-ng supported in operative position. Withdrawable stop pins I 9 or collars may be associated with the screeding member 9 to prevent endwise movement thereof' when in operative position.

The screeding tube is placed'in operative position as in Figures 1 and 2. The semi-dry or nonilowing material is introduced into the mold and the latter. is rotated in the direction of the arrow in Figure 2. The recesses Il of the plates Hare so disposed relative to the direction of rotation of the mold that the contact of the screeding tube 9 with the material within the rotating mold maintains the tube within the' recess while enabling it to rotate and exercise a rolling action upon the material which facilitates distribution and initial compacting of the material. After the material has thus been distributed the screeding tube may be withdrawn lengthwise from the mold and the latter then subjected to combined jolting or concussional and centrifugal actions as before referred to to complete themanufacture of the pipe or lining.

Having now described myv invention what IA claim as new and desire to `secure by Letters Patent is- 1. In apparatus for use in the manufacture or lining of pipes from semi-dry or non-flowing con` crete mixture, a rotary mold, means for rotating the mold to centrifugally apply the mixture to the n interior thereof, a rotary leveling andpressure member, and means for supporting same whereby it extends lengthwise from end to end within the mold in spaced relationship with the internal surface thereof so that, during rotation of the mold, the leveling and pressure member exercises a rolling action upon the mixture in order to evenlyspread or distribute it lengthwise and circumferentially .throughout the mold into the form of a partially compacted annulus ready for consolidation by combined concussion and centrifugal actions, the supporting means for said levelling and pressure member comprising upstanding arms or bearers located one at each end of the mold Aand provided with seatings for detachably receiving said member, said seatings being provided with open-sided recesses for rotatably accommodating the end portions of the member.

2. A device of the character described, comprising a rotary mold, a supporting frame, means on said frame for supporting and rotating said mold about a horizontal axis to centrifugally apply a concrete mixture to the interior thereof, a rotary pressing and leveling member extending longitudinallythrough said mold, a support for said member positioned at each end ofthe mold, each support comprising a seat for rotatably accommodating the end portions of said member and provided with an open side for the introduction and removal of said member, and means for adjustably securing said supports to said frame.

. C. C. HALKYARD. 

